Car stalling in the idle position

pasindu tharaka · July 6, 2020

I have a nissan FB 15 2002 car and couples of days before i faced a problem that when car is in idle position with D or R in gear with A/C car is stalling (like in the traffic) bt it's not happaning with the N or P and i replaced all 4 plugs,Air filter and i serviced injector nozzles as well bt problem is still remaining bt when driving in high RPM and when A/C off it's not hapanning..so guys please help me,this is such a annoying thing 4 me?

pasindu tharaka · July 6, 2020

I have a nissan FB 15 2002 car and couples of days before i faced a problem that when car is in idle position with D or R in gear with A/C car is stalling (like in the traffic) bt it's not happaning with the N or P and i replaced all 4 plugs,Air filter and i serviced injector nozzles as well bt problem is still remaining bt when driving in high RPM and when A/C off it's not hapanning..so guys please help me,this is such a annoying thing 4 me?

Davy · July 6, 2020

Hi @pasindu tharaka, welcome to the forum! Please refrain from creating multiple threads across different sections of the forum. I have now merged your threads.

As for your issue, I'd start by checking all the vacuum lines first for a leaks. Make sure all rubber vacuum hoses are properly secured and that they don't have cracks.

Next would be the idle air control valve that you should check. It might be sticking due to carbon deposits or faulty. Do a throttle body clean and get the IACV carefully cleaned as well.

HaeylM · July 7, 2020

Firstly is ur CEL on? (it would be a different diagnosis then)

Put your car on neutral, accelerate gradually until you have the throttle pressed fully down, hold it for about 10 seconds and let it go instantly. Observe how your car settles back to the idle rpm or if it drops low and start vibrating around like its going to stall/stalls. If this is the case then you might need to clean your throttle body and do a tuneup. (in some cars the car will keep swinging between a really low rev, almost stall then suddenly idle on a higher rpm, this will keep happening in cycles)

Also given that FB15 is almost a 20 year old car there may be considerable carbon deposits all over the engine components and some wear. ,may i suggest you to check your MAF and EGR

And if you feel the car jerk before dying, it could also be a case of your fuel pump being clogged up. (specially since you have mentioned that this happens when the A/C is on)

Edited July 7, 2020 by HaeylM

pasindu tharaka · July 12, 2020

I cleaned the throttle body

On 7/6/2020 at 3:02 PM, Davy said:

Hi @pasindu tharaka, welcome to the forum! Please refrain from creating multiple threads across different sections of the forum. I have now merged your threads.

As for your issue, I'd start by checking all the vacuum lines first for a leaks. Make sure all rubber vacuum hoses are properly secured and that they don't have cracks.

Next would be the idle air control valve that you should check. It might be sticking due to carbon deposits or faulty. Do a throttle body clean and get the IACV carefully cleaned as well.

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I cleaned the throttle body and the IACV value also and there was no any earrors showing with sensors when checking bt stalling is still happaning in the idle position with A/C

Davy · July 12, 2020

On 7/12/2020 at 4:14 PM, pasindu tharaka said:

I cleaned the throttle body

I cleaned the throttle body and the IACV value also and there was no any earrors showing with sensors when checking bt stalling is still happaning in the idle position with A/C

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When you start the car in the morning, does the RPM rise to around 1500 initially and gradually reduce to normal (i.e. around 700) as the engine reaches operating temperature?

Also, how did you clean the IACV? Did you spray a cleaning aerosol directly onto the valve?

pasindu tharaka · July 13, 2020

yep...i went to the A*W and a guy who working in there removed the IACV and just sprayed aerosol...and yesterday i told them abt this problem again ,and they asked me to replace the throttle body..so what shall i do....?

Davy · July 13, 2020

On 7/13/2020 at 10:03 AM, pasindu tharaka said:

yep...i went to the A*W and a guy who working in there removed the IACV and just sprayed aerosol...and yesterday i told them abt this problem again ,and they asked me to replace the throttle body..so what shall i do....?

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Was that a yes to the morning RPM behaviour? Please check my previous post and answer my first question.

If aerosol was sprayed directly onto the IACV, there's a possibility that the carb cleaner could have damaged the coils inside the IACV. From memory the QG15 engine has a plunger type IACV that needs to be cleaned with care. The correct way to clean it is to spray carb cleaner to a clean rag and wipe the IACV clean. If your car doesn't behave the way I've mentioned in my previous post, the IACV is likely to be faulty.

I think you should first check the IACV and then the Throttle Position Sensor before thinking of replacing the throttle body.

pasindu tharaka · July 13, 2020

On 7/13/2020 at 11:10 AM, Davy said:

Was that a yes to the morning RPM behaviour? Please check my previous post and answer my first question.

If aerosol was sprayed directly onto the IACV, there's a possibility that the carb cleaner could have damaged the coils inside the IACV. From memory the QG15 engine has a plunger type IACV that needs to be cleaned with care. The correct way to clean it is to spray carb cleaner to a clean rag and wipe the IACV clean. If your car doesn't behave the way I've mentioned in my previous post, the IACV is likely to be faulty.

I think you should first check the IACV and then the Throttle Position Sensor before thinking of replacing the throttle body.

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yep..in the morning RPM is behaving like you mentioned way and this problem is happening after driving few kilometers in the morning like when engine came to the operating temperature and when stalling ,i feel little a bit of shaking of the engine like lack of air or something..

Davy · July 13, 2020

On 7/13/2020 at 1:04 PM, pasindu tharaka said:

yep..in the morning RPM is behaving like you mentioned way and this problem is happening after driving few kilometers in the morning like when engine came to the operating temperature and when stalling ,i feel little a bit of shaking of the engine like lack of air or something..

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Your IACV sounds to be OK. If the problem only happens after the engine warms up (you never mentioned that before), and according to the symptoms described, it could be a faulty ignition coil.

Do you get a Check Engine light when the engine stalls?

pasindu tharaka · July 14, 2020

On 7/12/2020 at 11:04 PM, Davy said:

When you start the car in the morning, does the RPM rise to around 1500 initially and gradually reduce to normal (i.e. around 700) as the engine reaches operating temperature?

Also, how did you clean the IACV? Did you spray a cleaning aerosol directly onto the valve?

Expand

On 7/13/2020 at 11:08 PM, Davy said:

Your IACV sounds to be OK. If the problem only happens after the engine warms up (you never mentioned that before), and according to the symptoms described, it could be a faulty ignition coil.

Do you get a Check Engine light when the engine stalls?

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yep..when stalling check engine light is blinking and suddenly off and one of my friend also faced this problem and he told me after replacing his ECM he sloved this bt he has no such knowledge to explain what A*W did to his car..so how can i know faulty ECM and if i have any faulty With a Ignition coil can i find it by a nomal scan..bcz i have seen some diagnosis tools to check Ignition coils ,bt A*W in here they dont have that tool...?

Edited July 14, 2020 by pasindu tharaka